Implementation of PI2 queuing discipline for classic TCP traffic in ns-3
Rohit P. Tahiliani, Hitesh Tewari · 2017
This paper presents the implementation and validation of PI2Active Queue Management (AQM) algorithm in ns-3. PI2provides an alternate design and implementation to Proportional Integral controller Enhanced (PIE) algorithm without affecting the performance benefits it provides in tackling the problem of bufferbloat. Bufferbloat is a situation arising due to the presence of large unmanaged buffers in the network. It results in increased latency and therefore, degrades the performance of delay-sensitive traffic. PIE algorithm tries to minimize the queuing delay by auto-tuning its control parameters. However, with PI2, this auto-tuning is replaced by just squaring the packet drop probability. In this paper, we implement a model for PI2in ns-3 and verify its correctness by comparing the results obtained from it to those obtained from the PIE model in ns-3. The results indicate that PI2offers a simple design and achieves similar or at times better responsiveness and stability than PIE.